Re: Force Feedback
 

Thank you very much for the detailed explanation Al. I guess this means we really have two, final, final options. A Tesla coil delivering proper wattage routed through the joystick port without frying the OI or the people holding onto the joysticks, or an LED powered motor. Who's got the mylar?

Re: Force Feedback
 

You forgot the caveman option, give the coach a padded bit of PVC to whack the drivers with if they do something stupid. :D

Re: Force Feedback
 

Ha, the caveman option would be more like an unpadded pvc baton. The safety-renaissanceman would place a pad over the stick.:D

Re: Force Feedback
 

Something occured to me at a team meeting when I was telling a newbie about the time I was planning on turning an umbrella into a taser/cattle prod, why hook up the power from the LED to a joystick motor, when we could hook it up to the driver? We could tune it so it was like a prank buzzer but a bit weaker. Mind you, you wouldn't catch me driving it. :) But from a neurological point of view, this works very well, if you give a litle shock to someone when the motors are drawing too much current so their high speed relexes kick in and they will react much quicker. Or, one of those vibrating motors could be stuck in an armband for a cautionary warning, but that is so much less fun. To avoid frying the OI all this would have my earlier semivictor jobby, and if the arm counts as attached to the OI then we are already breaking the rules due to mitochondria.

Re: Force Feedback
 

What if the vibrating bit was optically isolated? Would that be kosher?

Re: Force Feedback
 

You have to power it from the OI, therefore it can not optically isolated. So one question that has to be answered is can the OI supply enough current to power the joystick and the vibrating motor?

Other questions that come to mind:

If the vibrating device is just a MOTOR with an unbalanced weight, can this be legal since in past years no additional motors are allowed?

On the other hand, if the vibrating bit was a totally self contained, i.e. you would have to open it up to discover that it was a motor with an unbalanced weight inside of a case, could it be legal?

Just some of the questions that come to mind.

Re: Force Feedback
 

The rules consistently define the robot in a way that does not include the OI. The "no additional motors" clause applies only to the robot, and by itself won't prohibit a motor connected to the OI.

Re: Force Feedback
 

Okay, so the setup would be like so. The LED driver connects to an LED, which is in a black plastic tube with a light sensitive resistor on the other end. The resistor is connected to a couple batteries and the vibrating motor, which is mounted on a strap that is put on the driver's arm. When the activation condition is met (too much current drawn, breaker blowing, low voltage, etc.) the LED is turned on, and the resistor allows current to flow to the vibrating motor. The motor then vibrates, warning the driver of that the condition has been met. This may not suppy much force, but it does give quick feedback, while allowing the drivers to keep their eyes on the field. It could also power speakers to give auditory feedback, but that would probably irritate allys.

Re: Force Feedback
 

I don't think I can agree on this one. The robot and the OI are often though of as one system. I would expect the rules makers to rule against this on those grounds.
To reiterate, all power at the driver station must be derived from the OI EXCEPT a computing device which connects to the Dashboard. A palm with visual, aural or motion monitoring could possibly be acceptable. We used a color palm with flashing red and yellow backgrounds for over current conditions a few years back and that was acceptable.

Re: Force Feedback
 

This thread is titled "force feedback", but if the intention is to alert the driver/operator to a condition like overcurrent or stall with out the driver taking her eyes off the field, then perhaps a piezo buzzer could be used. It should use less current than a motor and if it is mounted in the joystick, you might even be able to feel it.

Re: Force Feedback
 

The say the robot is a vehicle, which the OI isn't, then say you can't use extra motors on the robot.

Actually the rules never say this. They say that no AC power will be available and all equipment connected to the joystck port must be powered by the joystick port.

Re: Force Feedback
 

I can't seam to find it now but First ruled on many issues for the OI in the Qand A forum. Allot was discussed in2004.

Re: Force Feedback
 

luke, I think you and Al are saying the same thing. I do not understand the difference between your statement and Al's.

<R66> Teams are permitted to connect a portable computing device (Laptop computer, PDAs, etc.) to the RS232 Output of the Dashboard Port of the Operator Interface for the purpose of displaying feedback from the robot while competing in Competition matches. Please note that AC power will not be available at the playing field so these devices will have to run on internal batteries.

<R69> All equipment connected to the Joystick Ports of the Operator Interface must be powered solely through the power available through the port. External power sources of any type are not permitted on any equipment connected to the Joystick Ports. Portable computing devices may not be connected to Joystick input ports on the Operator Interface.


In short EVERYTHING connected to ALL of the joystick ports must be powered by the joystick ports. This is limited to 5V@100ma. If you want to use a battery in the operator station, then you must interface to the dashboard port and use computing device to provide the feedback. The question of whether a vibrating device made out of a motor is still a motor and can it be connected to the OI may have to wait until January to be answered.

Re: Force Feedback
 

I think that the question of using motors at the OI is one that hasn't been clearly addressed in the past and would be worth submitting a Q&A over. However, at this time (when we cannot submit Q&As), I wouldn't see any reason why they wouldn't be allowed provided that they meet the other requirements about power and the OI. To me it seems clear that the other robot rules are not applied to the OI so I don't know why this one would be. For example, thinking back to when we were restricted on what materials could be used on the robot, those restrictions did not apply to the OI. And, the OI is not weighed or sized with the robot, is not subject to inspection (at least according to the inspection checklist), etc. Plus, the rules have a separate section dedicated to the OI which are distinct from the rules that apply to the robot.

Re: Force Feedback
 

This is actually a good idea. The piezo I have here (Radio Shack) doesn't spec current draw but it might make enough noise to be heard. Although it is pretty loud in the driver's station.
Dave brings up a good topic for discussion. The OI hasn't been considered for materials in the past (other than hazardous) but those materials wouldn't give a team an advantage as they might on the robot. Although inspectors do not have a checklist item for the operator interface they do require it to be connected and powered for part of the inspection. Motors in the joysticks wouldn't be obvious at that time but other mods would. I still think of the robot as a system (even though it does have an autonomous mode) and the OI is part of that system.